You can, but you shouldn't rely on it — a verbal instruction can still count as a valid change to the work, but you're taking on the entire burden of proving what was said and at what price if it's ever disputed.
Short answer
Yes, but log it the same day. Treadstone Law’s guidance is direct: “A verbal instruction can still form part of a valid extra, but proving what was agreed — and at what price — becomes much harder without written confirmation.” The legal answer isn’t “no” — it’s that you carry the entire risk of proof unless you convert it to writing within hours, not weeks.
Treadstone Law’s guidance states it plainly: “A verbal instruction can still form part of a valid extra, but proving what was agreed — and at what price — becomes much harder without written confirmation.” So the legal answer isn’t “no” — a verbal instruction from a consultant or an owner’s representative can create a binding change to the work. The practical answer is that you’re taking on the entire burden of proof if it’s ever disputed, whether that dispute is about payment or about the scope itself.
“Get change orders in writing whenever possible, even a brief confirming email” — the article’s own advice, and the cheapest insurance available: a two-line email back to the consultant confirming what was said converts a verbal instruction into a written record within minutes.
If that’s genuinely not practical in the moment — an inspector on site telling you to change something before they leave — “Keep dated notes of verbal instructions if a written change order isn’t practical,” and follow up with written confirmation as soon as you reasonably can. “Track extras separately from the base contract so the value of each is clear” — don’t let a verbal instruction’s cost get buried inside regular progress billing where it’s indistinguishable from base scope, and don’t assume it covers idle time separately — see whether standby time caused by the same instruction is billable.
The same documentation gap that weakens a payment claim also weakens a lien claim if it comes to that — Ontario’s Construction Act preservation clock runs from your last supply of services or materials regardless of whether you can prove what was owed for it. A verbal-only record makes it harder to establish the value of what you’re preserving a lien for, not just harder to invoice.
A 30-minute call is enough to tell you whether AI pays for itself here.
